CRISPR Associated Proteins

Clustered regularly interspaced short palindromic repeats (CRISPRs) and their CRISPR-associated (Cas) proteins constitute the CRISPR-Cas immune system, which provides adaptive immunity against invasive elements such as viruses and plasmids in bacteria and archaea. Cas proteins are endonucleases that use a single guide RNA (sgRNA) to form complementary base pairs with target gene and then cleave the target at specific sites. Due to the programmability, high editing efficiency and ease of use , the CRISPR-Cas systems have emerged as a powerful tool for gene manipulation, with the type II CRISPR-Cas9 system from Streptococcus pyogenes already being widely adopted for various genome-targeting purposes. A distinct group of Cas proteins, including Cas12 and Cas13 among others, possess “collateral cleavage” activity that have been exploited and demonstrated in various diagnostic technologies.